Bedridden invalids are subject to numerous problems, including the inability to bathe adequately, the propensity to develop bedsores, and in the case of arthritic patients, the difficulty encountered in warming all the affected joints simultaneously. Thus, there has been a long felt need to provide such patients with an apparatus which will permit them to be immersed in water without leaving their beds. Evidence of this long felt need can be seen in U.S. Pat. No. 573,625 to Ruffner entitled "Invalid's Bath Tub", issued Dec. 22, 1896. Ruffner attempted to fill the need by providing a flexible liner which could be slipped under the patient and then given rigidity by inflating tubes judiciously built into the liner. A series of improvement patents continued to be issued up to the present day; most of the improvements attempting to solve the problem of inadequate rigidity. Some recent examples are U.S. Pat. No. 4,068,326 to Deschler and U.S. Pat. No. 3,681,789 to Bott.
Another avenue which has been taken in the attempt to solve this long felt need is to provide a rigid framework fastened to and supported by the bed, and in turn supporting a flexible liner. Examples of this type of solution can be found in U.S. Pat. No. 3,373,451 (Schmidt) and 3,246,346 (Schmidt). This concept depends from the invention described in U.S. Pat. No. 778,641 (Dudley, Redoubt), although that invention was not intended to be used in conjunction with a bed or invalids. These inventions solve the problem of inadequate rigidity found in inflatible tubs, but they suffer from complexity of assembly.